1. Field of the Invention
The present invention relates generally to a sign assembly comprising a base material, for example window glass, a sign framing member, and a sign display which is removable and replaceable.
2. Description of Related Art
Filmic display signs are well known. Self-adhesive film and static cling film window graphics are also known, in which a substrate material, for example a self-adhesive pvc or polyester film, is imaged with a design, such as an information sign or advertisement, and adhered to the surface of a window. Also known are see-through window graphics, for example, according to US RE37,186 and U.S. Pat. No. 6,212,805 comprising a partially imaged transparent panel allowing through-vision in one or both directions.
A major problem with such self-adhesive signs is that the stronger the adhesive, in terms of initial “tack”, the more difficult it is to reposition a sign if it is initially applied in an incorrect position or alignment, for example at a slope to the vertical, or with creases. High long term tensile, shear and peel strength also cause problems in the removal of such signs and are a significant part of the lifetime cost of so-called “space advertisements”, “point-of-sale” and other advertisements or signs which are regularly changed. Another inconvenience and cost is caused by adhesive staying on the window after removal of the film, so-called “adhesive transfer.” With alternatively available low tack and/or long term low adhesion pressure-sensitive adhesives or static cling films, the signs are easily removable, for example by a vandal wishing to take the sign. For this reason, frames are sometimes adopted to trap the sign against the base material, such as a window, to make unwanted removal more difficult.
Framing systems include so-called sprung clip profiles or sign framing members incorporating a cam profile which reacts again a resilient base material such as a fibre board. These prior art framing systems trap the edges of the imaged substrate and the sign framing members are in direct contact with the display sign. Hinged frames for containing display signs are also known, a rectangular frame assembly being typically hinged along one side of the frame, to enabling opening and insertion of a display sign.
In order to prevent the hinged, sprung or cam profiles being opened by a member of the public, one or more locking devices are typically incorporated. This unlocking, opening, closing and relocking adds to the time and cost of changing a display sign. Also, such mechanical hinged, spring clip or cam framing systems are typically of light construction and easily subject to vandalism, for example forced opening.